Direct detection of biomolecules in liquid media using piezoelectric rotational mode disk resonators

This work reports on direct detection of biomolecular adsorption events in liquid media using piezoelectric rotational mode disk resonators. Piezoelecrically transduced rotational mode silicon disk resonators with resonant frequencies in the 2.0-8.0MHz range capable of operating in liquid are utilized as direct real-time mass balances. The resonant frequency of the resonators was recorded in real-time while forming monolayers of 6-Mercapto-1-Hexanol (MCH) in aqueous solution. During one hour of exposure to the MCH solution, gradual frequency shift up to ~3600ppm was recorded which shows the capability of such resonators as highly sensitive biomolecular sensors. Detection of target ssDNA sequences has also been demonstrated using the same devices.